An automatic analyzer includes an analyzer that measures a physical property of a sample (e.g., a biological sample, such as serum and blood, or a mixture of a biological sample with a reagent), a sample processor that processes a sample in advance of measurement of a physical property of the sample, or a system that integrates the analyzer with the sample processor. The automatic analyzer includes processing units that perform a container cap opening process, a pipetting process, a container cap closing process, a mixing process, an analyzing process, and others and a transfer mechanism that transfers samples among different processing units.
The container cap opening process performs an uncapping process relative to a sample container on which a cap is mounted, wherein the cap on the sample container is opened. The pipetting process takes part out of the sample stored in the sample container after having been opened and discharges the part to another container. The container cap closing process performs a capping process relative to the sample container that has undergone predetermined processes including the pipetting process, wherein the cap on the sample container is closed again. The mixing process mixes the pipetted sample to thereby make its contents uniform. The analyzing process takes qualitative and quantitative measurements of the contents of the pipetted sample in which reaction is underway or completed.
Known arrangements for opening and closing the cap of the sample container (hereinafter referred to as an uncapping process and a capping process) in the container cap opening process and the container cap closing process of the sample processor are disclosed, for example, in Patent Documents 1 to 3.